Flexeril (cyclobenzaprine)

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Brand Name

Flexeril { McNeil Consumer & Specialty Pharmaceuticals}

Generic Name

cyclobenzaprine, pronounced sye kloe BEN za preen


What is Flexeril?

Flexeril is a medication that acts as a muscle relaxant. It helps you by blocking nerve impulses and pain sensations that may be sent to your brain. Along with physical therapy and rest Flexeril can be an effective medication to treat skeletal muscle injuries and pain.

Flexeril may also be used for other purposes that not listed in this medication guide.


Key Facts About Flexeril

You should not take Flexeril if you have used an MAO inhibitor like isocarboxazid (Marplan), tranylcypromine (Parnate), phenelzine (Nardil), or selegiline (Eldepryl, Emsam) within 14 days. Life-threatening effects may occur if you do not wait at least 14 days after stopping an MAO inhibitor before taking Flexeril.

Flexeril is in FDA pregnancy B. Flexeril is not expected to be harmful to an unborn baby, but you should tell your doctor if you are pregnant or plan to become pregnant. We do not know if Flexeril passes into breast milk or if it could harm a nursing baby. You should not breast-feed while taking Flexeril. Talk to your doctor about any concerns you may have if you are pregnant or recently gave birth and are taking Flexeril.

You should be aware that drinking alcohol may increase the effects of Flexeril, so you should not drink while taking this medication.

Flexeril may impair your thinking and reaction time. Be careful when driving or doing anything that requires you to be alert, especially when you first start taking Flexeril.


Before You Take Flexeril

If you are allergic to cyclobenzaprine you should not take Flexeril.

You should not take Flexeril if you have recently had a heart attack, or if you have congestive heart failure, a heart block, a heart rhythm disorder or an overactive thyroid.

Do not take Flexeril if you have used an MAO inhibitor like isocarboxazid (Marplan), tranylcypromine (Parnate), phenelzine (Nardil), or selegiline (Eldepryl, Emsam) within the past 14 days.

Tell your doctor if you regularly use allergy or cold medications, narcotic pain medicine, sleeping pills, medications for seizures, depression or anxiety, as these drugs can lead to excessive sleepiness caused by Flexeril.

Let your doctor know if you use another muscle relaxer before taking Flexeril.


Flexeril Drug Interactions

You should inform your doctor if you are taking any of the following:

  • atropine (Donnatal)
  • benztropine (Cogentin)
  • bronchodilators like ipratroprium (Atrovent) or tiotropium (Spiriva)
  • dimenhydrinate (Dramamine)
  • glycopyrrolate (Robinul)
  • guanethidine (Ismelin)
  • irritable bowel medications like dicyclomine (Bentyl), hyoscyamine (Anaspaz, Cystospaz, Levsin, and others), and propantheline (Pro-Banthine).
  • mepenzolate (Cantil)
  • methscopolamine (Pamine)
  • scopolamine (Transderm-Scop)
  • tramadol (Ultram)

Other drugs you take that are not listed may interact with Flexeril. You should tell your doctor about all of the medications you use. This includes prescription drugs, vitamins, supplements and herbal products, and over the counter medications. You should not begin taking a new medication without telling your doctor first.


Directions for Taking Flexeril

Flexeril is usually prescribed as a medication to take with or without food. You should take Flexeril exactly as it is prescribed by your doctor. Your doctor may change your dose to make sure you get the best results from Flexeril. You should follow the instructions on your prescription label and not take Flexeril for longer than recommended by your doctor, or in larger or smaller doses.

Flexeril should be taken with a full glass (8 ounces) of water.

Flexeril is a part of a complete program of treatment your doctor has prescribed. Other parts of this program may include rest, physical therapy, or other pain relief measures. Be sure to follow your doctor’s instructions exactly.

Flexeril needs to be stored at room temperature, and away from light, moisture and heat.

If you miss a dose of Flexeril you should attempt to take the missed dose as soon as you remember. However, if it is almost time for your next scheduled dose do not take the missed dose in addition to your regular dose.


Flexeril Side Effects

If you experience any of the following adverse effects you should stop taking Flexeril and seek emergency medical help immediately:

  • allergic reaction signs, like breathing difficulties, hives and swelling of your face, lips, throat or tongue
  • bleeding or easy bruising
  • chest pain or heavy feeling, pain spreading to the arm or shoulder, nausea, sweating with a general ill feeling
  • clay colored stools
  • confusion, weakness and lack of coordination
  • jaundice or yellowing of your eyes and skin
  • headache, confusion, and problems with vision, speech, or balance
  • feeling faint
  • fluttering or pounding heartbeat
  • loss of appetite
  • low grade fever
  • nausea
  • numbness or weakness, especially on one side of the body and is sudden
  • seizures
  • stomach pain
  • unusual thoughts or behavior or hallucinations
  • urine that is dark in color
  • weakness (extreme or unusual)

Less serious Flexeril side effects may include:

  • blurry vision
  • constipation
  • diarrhea
  • dizziness
  • drowsiness
  • dry mouth
  • dry throat
  • exhaustion
  • gas
  • loss of appetite
  • muscle weakness
  • nausea
  • stomach pain

It should be noted that this is not a complete list of possible side effects of Flexeril. You should contact your physician for a complete list and medical advice regarding these effects.


Flexeril Description and Dosing

Flexeril is available in both 5mg and 10mg tablets. The 5mg tablets are yellow-orange, 5-sided, D-shaped, film coated and coded FLEX over 5 on one side and without coding on the other side. The 10mg tablets are butterscotch yellow, 5-sided, D-shaped, film coated and coded Flexeril on one side and without coding on the other side.

Flexeril is dosed based on individual conditions and situations. Your doctor will prescribe a dose for you that is best for treating your particular injury or condition. You should not attempt to alter or change your dose without your physician’s consent.

If you suspect that you have overdosed with Flexeril you should seek emergency help immediately.


Ingredients in Flexeril

The primary active ingredient in Flexeril is Cyclobenzaprine HCl. Other ingredients include hydroxypropyl cellulose, hypromellose, lactose, magnesium stearate, starch, titanium dioxide, Yellow D&C #10 Aluminum Lake HT, and Yellow FD&C #6 Aluminum Lake in the 5 milligram tablet. The 10 milligram tablet also contains hydroxypropyl cellulose, hypromellose, iron oxide, lactose, magnesium stearate, starch, and titanium dioxide.

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The information contained in this drug guide is intended as an educational resource only. This guide is not exhaustive and does not contain all available information about this drug.This guide is not intended as medical advice for individual conditions or treatment.

The information provided in this guide does not replace the need for the advice and services of medical professionals or the need for medical examination. Always talk to your physician or pharmacist before taking any prescription medication or over the counter drugs (including any supplements) or before making any changes to your treatment. Only your doctor, nurse or pharmacist can provide you with safe and effective advice regarding your drug treatment.

The use of the information in this guide is at your sole risk. This information is provided "AS IS" with no warranties to accuracy or timeliness.

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